Etymologically this name means "the dark cave". Baume comes from a latin name "balma" which defines a cave shelter, a cavern, a cavity.
Nine cavities more or less important were inventoried on the site of "Baume Obscure". Three of them link together : the cave of Cyprès, the cave "de la Loube" and the cave "Services".
They form an underground network of 1200 meters long and 80 meters deep. A part of it, of 700 meters approximately, has been accomodated with stairs and bridges in order to make the visit of the galeries and the most interesting rooms possible.
From discovery to accomodation :
It is in the Cyprès' cave, on April 6' 1958 and at 22 meters from the entrance, that the speleologists from the Martel Club (Alpine Club of Nice) enlarged a path. It will allow them to access the large galeries and the river situated 50 meters downwards. The discovery of that relatively easy access caused immoderate frequent visits of the cave in the following years. Resulting degradations - broken concretions by mistakes or simple unhandiness - decided speleologist Henri Chabert to buy the cavity in 1982 in a view to close it and equip it for visits. This stopped the deterioration of the site. It saved Baume Obscure from the irreparable loss of most of its crystallizations. They can nowadays be admired by everybody.
Henri Chabert, Denis Allemand, Jean-Marie Chabert and Pierre Crozatier are the speleologists who decided to equip the cave in 1982. In order to do so, they first had to reach the upper rooms of the Cyprès' cave via the cave "de la Loube". Between them : a 40 meters long galery totally filled with clay. After long and painful removal of obstructions, the accomodation works could start. Ten years and 10000 hours of hard work were necessary to enable easy and safe visits. Thanks to works done in the Cyprès's cave the path was then considerably improved. By entering via a cavity and exiting by another, they allowed visitors not to walk backwards and suffer from uncomfortable crossings in narrow portions of the galery. In 1996, under the new owner, this galery crossing was embellished by an audiovisual show using a futurist technology of animation by sounds, images and lights. The path avoids walking there and back as well as fastidious crossings.
The cave to-day
Baume Obscure constitues nowadays an unrivalled site open to everybody to discover the multiple facets of a mediterraneen karst (southern karst of the Prealpes of Grasse), on surface as well as underground : its specific geology,mineralogy and hydrography, its fauna and flora, its cultural and historical inheritance.The cave offers a complete picture of the hydrological phenomenons and mineral beauty that are hidden under the calcereous tableland of Saint-Vallier de Thiey.
The formation of concretions is plentiful and several formations are exceptional : huge fistulous some of them measuring more one meter, , bush of aragonit, eccentric concrétionsof pure calcite (transparent like ice) of amazing shapes. The more classical concrestions like drapery, pillar, stalagmitic and stalactitic, calcite flow, make a particularly aesthetic scenery, especially in the three best rooms of the cavity : the Balcony room, the Gours room, the Dôme room (also salled the Organs room). The fossils, notably the guards of belemnites (forefather of the tidal wave, seiche) bring to remembrance the sea and lacustrian origins of the calcereous stone in which the caves were born millions of years ago (secondary era : jurassic)
Two new groups of molluscs originated out of the not too deep oceans of the Jurassic : the ammonites and the belemnites.They were two kinds of squids, far parents of our actual nautilus, octopus and seiches.
These two species disappeared at the same time than the dinosaurs by the end of the Cretaceous. Although very numerous, they could not adapt to the change in temperature and salinity of waters.
Belemnites have a hard internal body made of calcite. This hard part was looking like a gun bullet which to-day we can generally see only the outside end : the guard.
The waters that circulate inside the caves form a complex flowing network with multiple origins and destinations. Three junctions and one diffluence have been visually identified by speleologists. At raining times, the flow can reach several litres per second but only in very few occasions will the cavity be flooded not permitting visits.
Baume Obscure is effectively not a so-called "active" network. It is a "fossil" network that was abandoned by waters which dug it and then was totally closed by clay before being partially emptied by temporary aquatic currents not necessarily using the existing old galeries.
Waters from the cavity form one of the numerous affluents of the river Foux of Saint-Cezaire-sur-Siagne. Since some years, subsequent to numerous speleological discoveries (more than 20 kilometers of galeries explored and recorded) we know that the waters from Baume Obscure join downstream the huge galeries where the main river flows. This rivers collects the main part of the waters coming from the tableland of Saint-Vallier de Thiey and emerging at La Foux of Saint-Cezaire in the gorges of the Siagne.
The proof was brought in March 1967 thanks to the colouring of the waters with 15 kilos of fluoresceine (operation performed by the Club Martel of Nice). The colorant reappeared 6 days later at la Foux of Saint-Cezaire, i.e. 300 meters downstream and 5000 meters farther (in straight line but much more in reality considering the underground winding path !). The maximum flowing speed was then evaluated to 30 meters per hour.
The Souterroscope : A superb educational tool to underground environment
The path starts at the historical entrance - the Cyprès' cave - and ends by the Cave of "la Loube". The two holes are distant by one hundred meters approximately.
Approximate lenght of the path : 700 meters.
First a going down to the water level through a network of galeries down to 60 meters deep. Then a going up to the surface via successive rooms rich in concretions : Balcony room, Gours room, Dôme room (and Grand Organs).
Average duration time : one hour. They let the visitor being free to stop and go where and whenever he wants to. That freedom makes the originality of the Souterroscope : everybody can discover the cave at his speed : look, listen, take pictures or videos.
A secured path :
Along the path the monitoring is done using a video and voice system.
A portable electric light is provied by mean of security but also to discover the cave the same way as speleologists. During a few seconds, between two illuminations, the visitor is brought in the same atmosphere than a speleological exploration .He discovers the underground world in its primary aspect and can concentrate his light ray on details that are hardly noticable with the automated lightening..On top, a tresor hunting is available to the kids, a true introduction to geocaching !
Link to the time table and fee :http://www.baumeobscure.com/info.htm
Link to a TV report : http://www.baumeobscure.com/video/video.htm
Earthcache validation :
In order to log this earthcache, yous must complete the following coordinates by answering educational questions of geological nature and also questions which answers you will find on site at the caves in order to prove your visit, then enter them into the geochecker where a WORD to be mandatory used in your log is given to validate your find.
ANY NOT COMPLIANT LOG WILL BE DELETED WITHOUT PRIOR NOTICE.
N 43° 39. ABC E 006°48.DE
1. The formation of this set of caves that constitute the Souterroscope took place : answer 1 = during the primary era, answer 2 = during the secondary or answer 3 = during the tertiary. Put the correct answer number as A.
2. The souterroscope is made of a set of caves that link together. There are : answer 2 = 2 caves, answer 3 = 3 caves or answer 4 = 4 caves. Put the correct answer number as B
3. The sea fossils present in these caves and that we can recognize at their guards having the shape of gun bullets are :answer 3 = amonites, réponse 4 = siréniens or answer 5 = belemnites. Put the correct answer number under C
4. On the ceiling of a room, a particular shape of concretions can be observed. It looks like : answer 4 = shark teeth, answer 5= crocodile jaws or answer 6 = bird feathers. Put the correct answer number under D
5. Inside one galery that you cannot enter, there is the representation of an animal that fell in a hole of the cave and was found died. It is : answer 10 = a fox, réponse 11 = a dog or answer 12 = a roe-deer. Put the correct answer as E
6. And last, but not least, take a picture of you with your GPS on hand either at the entrance of the cave, or inside the caves (flash permitted) or at the exit of the cave in front of the speleologist mannequin.
You do not have to go to the coordinates that you will find in the geochecker, they are cosmetic and just here to prove that you visited the site. So you can relax and validate the geochecker on your return.
I hope you enjoyed the visit. There is another souterroscope belonging to the same organization close to Caen in Lower-Normandy and which earthcache reference called "les ardoisières" is GC3J4TA.